feat: add recipe translation tool with AI translation and settings management

- Add Word document parsing and translation export
- Add database configuration management
- Add AI/LLM translation configuration
- Add translation vocabulary management
- Add export settings (colors, page orientation, headers)
- Separate database and AI configurations
- Add debounced search to prevent database overload

lib/database.ts

@@ -0,0 +1,67 @@
+import mysql from "mysql2/promise";
+
+const pool = mysql.createPool({
+  host: process.env.DB_HOST || "127.0.0.1",
+  port: parseInt(process.env.DB_PORT || "3306"),
+  user: process.env.DB_USER || "root",
+  password: process.env.DB_PASSWORD || "",
+  database: process.env.DB_NAME || "recipe_tools",
+  waitForConnections: true,
+  connectionLimit: 10,
+  queueLimit: 0,
+});
+
+export default pool;
+
+/**
+ * 根据中文菜名查询英文翻译
+ * @param chineseName 中文菜名
+ * @returns 翻译结果或 null
+ */
+export async function getTranslation(chineseName: string): Promise<string | null> {
+  try {
+    const [rows] = await pool.execute<mysql.RowDataPacket[]>(
+      "SELECT english FROM words WHERE word = ? LIMIT 1",
+      [chineseName]
+    );
+
+    if (rows.length > 0 && rows[0].english) {
+      return rows[0].english as string;
+    }
+    return null;
+  } catch (error) {
+    console.error("Database query error:", error);
+    return null;
+  }
+}
+
+/**
+ * 批量查询翻译
+ * @param chineseNames 中文菜名数组
+ * @returns 翻译结果映射 { chineseName: englishName }
+ */
+export async function getTranslations(
+  chineseNames: string[]
+): Promise<Map<string, string>> {
+  const result = new Map<string, string>();
+
+  if (chineseNames.length === 0) return result;
+
+  try {
+    const placeholders = chineseNames.map(() => "?").join(",");
+    const [rows] = await pool.execute<mysql.RowDataPacket[]>(
+      `SELECT word, english FROM words WHERE word IN (${placeholders})`,
+      chineseNames
+    );
+
+    for (const row of rows) {
+      if (row.word && row.english) {
+        result.set(row.word as string, row.english as string);
+      }
+    }
+  } catch (error) {
+    console.error("Database batch query error:", error);
+  }
+
+  return result;
+}